Dry mouth every night, may be related to physiological factors, may also be due to hyperthyroidism, diabetes, dry syndrome and other causes. 1. Physiological factors: such as the environment in the climate is too dry, not enough water during the day, or not enough indoor humidity, etc., may lead to dry mouth every night. 2. Hyperthyroidism: due to the patient’s thyroid hormone secretion is too much, resulting in an increase in the body’s basal metabolic rate, which may cause dry mouth at night, can also be accompanied by easy to lose their temper, hyperphagia, emaciation and other manifestations. 3. Diabetes: usually due to poor glycemic control in diabetic patients, when blood sugar rises, leading to symptoms of polyuria, resulting in a large amount of water discharged from the body, which may cause dry mouth every night. 4. Dry syndrome: the disease is mainly an autoimmune disease that attacks the patient’s lacrimal and salivary glands, the patient’s typical symptoms of dry eyes, dry mouth, which may lead to the patient’s dry mouth every night, but also may be accompanied by loss of taste, tongue dryness, pain and other symptoms. Dry mouth every night may also be caused by other reasons, if accompanied by other obvious discomfort, you should seek medical attention as soon as possible to clarify the cause, and then give targeted treatment.